Backpack Fit Measurement Guide
Find the pack that fits your body, not just your gear list.
Torso length is the single most important measurement when buying a backpack. This guide helps you measure correctly, match your body to the right pack size, and compare sizing across Osprey, Gregory, Deuter, and Kelty. No guesswork. No returns.
Step 1: Measure your torso
You need a flexible measuring tape or a piece of string and a ruler.
- Find your C7 vertebra. Tilt your head forward. The bony bump at the base of your neck is your C7. That is your starting point.
- Find your iliac crest. Place your hands on your hips with thumbs pointing back. The top of your hip bones is your iliac crest. That is your end point.
- Measure between them. Run the tape measure down your spine from C7 to the level of your hip bones. Keep it against your back, not bending forward.
- Record the number. Measure in inches or centimeters. Do not round up or down. Use the exact number.
Common mistakes
- Measuring total height instead of torso. Your legs do not matter for pack fit.
- Measuring over your shirt. Measure against your back or in a thin shirt. Thick layers add inches.
- Bending forward while measuring. Stand straight. Bending shortens the measurement.
- Using your pant size. Waist size and torso length are not the same thing.
Step 2: Enter your measurements
Enter your measurements and press "Get my pack size" to see your results.
Brand size chart comparison
Once you know your torso length, use this table to find your size at each brand. Sizing is not universal. A medium at Osprey is not the same as a medium at Gregory.
| Torso range | Osprey | Gregory | Deuter | Kelty |
|---|---|---|---|---|
| Under 43 cm (17") | XS / XXS | XS | Extra Small | XS |
| 43-48 cm (17-19") | S / Small | S | Small | S |
| 48-53 cm (19-21") | M / Medium | M | Medium | M |
| 53-58 cm (21-23") | L / Large | L | Large | L |
| Over 58 cm (23") | XL | XL | Extra Large | XL |
Women's specific packs often run 1-2 cm shorter in each size range. Check the brand's women's chart if you are using a women's harness.
Load range by pack volume
Volume tells you how much fits inside. Load range tells you how much weight the pack is designed to carry comfortably. These are general guidelines. Your fitness level and trip conditions matter too.
20-30 liters
Daypack
Best for: day hikes, commuting, school.
Comfortable load: 4-8 kg (9-18 lb).
30-45 liters
Light overnight
Best for: weekend trips with a tent or hut access.
Comfortable load: 8-12 kg (18-26 lb).
45-60 liters
Standard backpacking
Best for: 2-4 nights in the backcountry.
Comfortable load: 12-18 kg (26-40 lb).
60-75 liters
Extended trips
Best for: 5+ nights, winter gear, or carrying group equipment.
Comfortable load: 18-25 kg (40-55 lb).
75+ liters
Expedition
Best for: mountaineering, long remote trips, or ultralight beginners who pack bulky gear.
Comfortable load: 25+ kg (55+ lb).
Rule of thumb for beginners
Start with a pack that holds no more than 20% of your body weight when fully loaded. If you weigh 70 kg, aim for a total pack weight under 14 kg. As you gain experience and shed unnecessary gear, you can move to larger volumes.
Printable measurement record
Take this card to the store. It has everything a gear shop needs to fit you correctly. Print it or save it to your phone.
My Pack Fit Record
Date:
My brand sizes:
Osprey: -- | Gregory: -- | Deuter: -- | Kelty: --
When the pack still does not feel right
Even with correct sizing, a pack may need adjustment. Try these before returning it.
- Load the pack with 10-15 kg. An empty pack fits differently than a loaded one. Most shops have weighted bags for testing.
- Tighten the hip belt first. The belt should sit on your hip bones, not above them. Snug it before touching the shoulder straps.
- Adjust the load lifters. These small straps above your shoulders pull the top of the pack closer to your back. They should be at roughly a 45-degree angle.
- Check the sternum strap height. It should sit across your chest, not your throat. It stabilizes the shoulder straps but does not carry weight.
- Walk for at least 10 minutes. Stand in the store for a few minutes, then walk. A pack that feels fine standing may shift when you move.